John f



(No Model.)

' J. F. KELLY.

INDUCTION COIL.

No. 404,630. Patented June 4, 1889. ,0 1711972. 5 13 d.

UNITED STATES PATENT OFFICE.

JOHN F. KELLY, OF IIOBOKEN, NEW JERSEY, ASSIGITOR TO THE UNITED S'lA ES ELECTRIC LIGHTING COMPANY, OF SAME PLACE.

INDUCTION-COIL.

SPECIFICATION forming part of Letters Patent No. 404,630, dated June 4, 1889.

Application filed October 30, 1886. Serial No. 217,563. (No model.)

To all whom it may concern.-

Be it known that I, JOHN F. KELLY, a citizen of the United States, residing at Hoboken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Induction-Coils, of which the following is aspeciiication, reference being had to the drawings accompanying and forming a part of the same.

This invention is an improvement in the iinluction-coils or converters used in electric lightin and similar systems for the purpose of inducing from the main or generator current one or more secondary currents to be used for operating the lamps or other translating devices.

It has been found, in connection with devices of this kind, that their practicability and efficiency are very greatly increased, or, in fact, dependent upon certain structural conditions. It is desirable, in the first place, that there should be present within the limits of theinductive action of the coils a relatively large mass of iron, which should form or approximate to a closed magnetic circuit; second, that the entire coil should be inclosed in or surrounded by iron, and, third, that the iron throughout should be laminated or its continuity broken up as far as possible. I have invented a converter or inductorinm which fulfills these requirements and which forms a very simple and e'iiicient instrument. I construct the instrument by building up a core composed of iron plates with intervening insulating material containing grooves in their opposite sides. In these grooves I wind the two coils, the primary and secondary, side by side or in any other way. Over the core and coils I then build up an inclosing-casing or armature of iron alternating with insulating-rings, and I secure the whole together by tie-rods and nuts, or in other convenient manner.

The invention resides in the peculiar construction and combination of the several parts.

In the drawings hereto annexed, Figure 1 is a side elevation and part section of a complete converter constructed in accordance with my invention. Fig. 2 is a vertical central section of Fig. 1. Fig. 3 is a horizontal cross-section of Fig. 1. Fig. 4. is a plan view of one of the end pieces or plates. Fig. 5 is a plan view of one of the plates composing the core. Fig. 0 is a portion of one of the rings forming the inclosing-case.

A in Fig. 2 is the core; 13, the suroundingcase; (i (l, the iron heads or end plates; 1), one of the coils, and F the base upon which the device rests.

In building up the device I placea number of plates of soft iron G upon one another, alternating with sheets of paper or other like material to break up the continuity of the metal. Each plate is of generally circular form, with two diametrically-opposite recesses H l I, which form longitudinal grooves in the completed core. In these grooves the primary and secondary coils I) E are wound. The relative size of wire or length of the coils will be varied in accordance with well-understood laws to meet the reipiiremcnts of particular cases.

Over the coils when wound a casing or armature of iron is formed by a number of superposed iron rings K, which are slipped over the coils and core. These rings are separated from one another by strips of paper, or in other convenient ways. They form a tube of equal length with the core. The compound core is then secured by iron heads 0 C and rods L L, which serve to bolt the heads together. Rings of insulating material M insulate the core from the heads 0, and hard rubber gaskets and washers N around the rods L and under the nuts 0 insulate the heads from one another. The heads are of larger diameter than the rings K, or are otherwise adapted to project over them, and they have perforations into which the coils at the ends of the core extend. The ends of the coils may be taken out at either end of the coil through the openings in the heads C.

By this construction the coils are practically inclosed by an iron casing, which forms a closed magnetic circuit, or, in other words, serves as an armature between the ends of the plates G. The iron is also divided up into such nunierous sections as to give the best results. In this device there is only a trifling loss in conversion. The local action or heating of the core or coils is practically avoided and the construction and mode of operation is such that the self-induction and counter electro-motive force of the primary coil, When other things are equal, is nearly proportional to the resistance of the secondary.

WVhat I claim as new isv 1. lhe combination, with a sectional longitudinally-grooved core and primary and secondary coils Wound thereon, of a sectional casing or armature surrounding and inclosing the core and coils, as set forth.

2. The combination, with a core formed of recessed iron plates with interposed sheets of insulating material, and primary and secondary coils Wound longitudinally around the core in the grooves formed by the recesses of the plates, of a casing composed of perforated plates or rings of iron with interposed insulating material built up around the coils and core, as set forth.

3. The combination, With a core composed of recessed iron plates with interposed sheets of insulating material and primary and secondary coils Wound longitudinally around the core in the grooves formed by the recesses of the plates, of a casing composed of aseries of iron rings with interposed insulating material, closely fitting the core, and means for binding the parts together, as and for the purpose set forth.

4. An induction coil or transformer of alternating electric currents, consisting of a sectional iron core provided with grooves or channels, primary and secondary conductors, and an outer sheathing, the primary and secondary conductors being wound in the same grooves or channels, and being equally close to both the core and the sheathing, as set forth.

JOHN F. KELLY.

Witnesses:

MosEs J. DE WITT, CHAS. E. BALDWIN. 

